Tubing latch



Nov. 22, 1960 E. L. MEDFORD, JR

TUBING LATCH 2 Sheets-Sheet 1 Filed Dec. 13, 1957 INVENTOR.

Erskin Lynn Medford, Jr BY W BM- ATTORNEY NOV. 22, 1960 MEDFORD, JR2,961,047

TUBING LATCH Filed Dec. 13, 1957 2 Sheets-Sheet 2 INVENTOR. Erskl'n LynnMedford, Ji'.

ATTORNEY United States Patent Ofiice 2,961,047 Patented Nov. 22, 1960TUBING LATCH Erskin L. Medford, Jr., Duncan, kla., assignor toHailiburton Oil Well Cementing Company, Duncan, Okla.

Filed Dec. 13, 1957, Ser. No. 702,717

1 Claim. (Cl. 166-123) This invention relates to a novel device that isadapted to connect and disconnect a conduit in a well bore from a stringof tools below it. More particularly, the invention relates to a devicewhich is adapted to disconnect a string of well tubing from a packerassembly which is set in a cased well bore.

After an oil well is drilled, and it is decided that such Well hascommercial possibilities, a conduit, referred to as a casing, is placedin the bore, so drilled, and cemented to the walls of the well bore bymethods which are well-known in the art. The flow passage for thepetroleum products from the well bore generally consists of a smallerconduit, usually referred to as tubing, and which is disposed insidesuch casing. Whereas, the casing is permanently anchored in the wellbore by cementing, the tubing is very seldom permanently anchored insidethe casing. For many reasons well-known in the art, it is frequentlydesirable or necessary to remove the tubing.

Such tubing is temporarily anchored in the casing by such well-knowndevices as packers or hangers. There are many variations of packers andmethods of setting them. A common type is called a production packer. Itis attached to the lower end of a string of tubing and at the desireddepth, the packing elements are compressed, so that the component partsfirmly engage the Walls of the casing, and thus anchor or support thetubing.

Such packers once set inside the casing are more or less permanent andusually are removed by drilling operations. Various methods are employedin separating a string of tubing from a set packer, in order that thetubing may be removed from the well bore, while the packer remains inplace. One well-known method involves the employment of J-slots whichrequire some rotation of the tubing in order to separate the tubing fromthe packer. Other methods merely involve pulling the tubing loose fromthe packer. It can readilv be seen that in such methods various problemswill be encountered when it is desired to reconnect the tubing to thepacker.

Therefore. it is an object of this invention to provide a novel devicewhich will connect or disconnect a string of tubing to a packer set in acased well bore by up and down movement of the tubing.

It is another object of the invention to provide a device which providespositive latching action between a string of tubing and a set packer.

It is still another object of the invention to provide a device whichwill successively latch and unlatch a string of tubing to a packer setbelow it as frequently as is desired.

These and other objects and advantages of the invention will be readilyapparent when taken in connection with the following description andaccompanying drawmg.

in the drawing:

Figure 1 is a sectional view in elevation, showing the apparatus of theinvention disposed between a string of tubing and a packer assembly, andillustrates the position of the component parts as the entire assemblyis lowered into a cased well bore.

Figure 2 is a sectional view in elevation showing the position assumedby the component parts of the invention, as the packer assembly is setto engage the walls of the casing in the well bore.

Figure 3 is a sectional view in elevation showing the position of thecomponent parts of the invention in the unlatched position, wherein thetubing string is disengaged from the set packer assembly.

Figure 4 is a sectional view in elevation showing the position of thecomponent parts of the invention just prior to positively latching thetubing to the set packer assembly.

Figure 5 is a sectional view in elevation showing the position of thecomponent parts of the invention in the latched position.

Referring to the drawing in detail, and first to Figure 1, it will beseen that the assembly consists of a string of tubing 10, a tubingextension 25, a latching assembly 14 and a packer assembly 12 disposedin a cased well bore 16. The string of tubing 10 is shown connected tothe packer assembly 12 by means of a tubing latch assembly 14 and asleeve 15. One function of the sleeve 15 is to hold the packer assembly12 and the tubing 10 in fixed relat onship by means of threads 17 and 21as the entire assembly is lowered into the cased well bore 16. Whendesired the sleeve 15 can be pulled in two as shown in Figure 2. Thepacker assembly 12 is of any conventional type, such as a product onpacker. It consists of a mandrel 18, a resilient material 20, and slips22 and 22a. Disposed inside of and in fixed relationship to the mandrel18 is a latch ring 24. The latch ring 24 is retained in fixedrelationship to the mandrel 18 between an inter or shoulder 31 on themandrel 18 and the lower end of the sleeve 15. A sleeve 19 is retainedin the interior of the mandrel 18 by the lower portion of the latch ring24 and a shoulder 33 on the mandrel 18. The function of the sleeve 19 isto limit the outward movement of the fingers 26a. The tubing extension25 extends downwardly from the tubing latch assembly 14 through thereduced inner diameter of the mandrel 18.

The tubin latch assembly 14 includes a cvlindrical bodv 14a which isconnected to the tubing 10 by any suitable means such as threadedcoupling 27 and to the tubing extension 25 bv any suitable means such asthe threads 23. concentrically mounted about the bodv 14a i a fingerring 26. concentrically mounted around the finger ring 26 is a slee ering 28. Both the finger ring 26 and the sleeve ring 28 are free to movelongitudinally aro n the cvlindrical body 14!: of the tubing latchassemblv 14. The finger ring 26 has a plurality of downwardlv nro ectingfin ers 26a which are normally biased outwardly as shown in Figures 1, 4and 5. The finger r ng 26 is preferablv formed from a material havingspr ng-like characteristics, such as spring steel, which nerrnits thefingers 26'? to be compressed as shown in Figures 2 and 3 and thenreturn to their normally biased pos tion as shown in Figures 1, 4, and5.

Downward movement of the fingers 26a is limited by a shoulder 30 on theupper end of the tubing extension 25 Upward movement of the finger ring26 and the sleeve r ng 28 is limited by a shoulder 32 provided in thecylindrical body 14a of the tubing latch assembly 14.

The fingers 26a of the finger ring 26 are provided with shoulders 26bwhich are adapted to engage the bottom surface of the sleeve ring 28 asshown in Figures 2 and 3.

The outer diameter of the sleeve ring 28 is slightly larger than theinner diameter of the latch ring 24. Upon the application of suflicientlongitudinal force the 'tively to the packer assembly .12.

. 3 sleeve ring 28 will compress sufliciently so that the outer surfaceof the sleeve ring 28 will be forced into the barrel of the latch ring24.

The operation of the embodiment of the invention is as, follows: r r

The packer assembly 12 is set to engage the cased well bore 16 in theconventional manner, which involves rotating the tubing to set the upperslips 22 and raising the tubing to set the lower slips 22a. Asillustrated in Figure 2 the resilient material 29 and the slips 22 and22a are set to firmly engage the cased well bore 16. Continued upwardpull on the tubing 10 is applied until the sleeve is parted. The tubing10 and tubing latch assembly. 14 are thus separated from directconnection with the mandrel 18 of the packer assembly 12.

In order. to positively connect the tubing 10 to the Packet assembly 12,the following operations which are illustrated in Figures 4 and 5 of thedrawing are performed. 2

The tubing 10 is lowered into the cased well bore '16 and the tubinglatch assembly 14 enters the mandrel 18 of the packer assembly 12.Sufficient weight at the surface is applied to the tubing 10 sothat thefinger ring 26 is pushed downwardlyand through the latch ring 24 bymeans of the shoulder 32. The fingers 26a of the finger ring 26 are thenfree to expand. The sleeve ring 28, as previously stated, has an outsidediameter slightly larger than the inside diameter of the latch ring 24and since the tubing 10 is not lowered sufiiciently to.cause theshoulder 32 to force the sleeve ring 28 into the latch ring 24, itremains above they latch ring 24. Then by pulling upward on the tubing10 and putting it in tension 7 the shoulders 26b of the fingers 26aengage the bottom of the latch ring 24 thereby latching the tubing 10posi- In this position, a variety of oil well operationscan beperformed. The tubing 10 can beutilized to, provide a conduit for theflow of hydrocarbons from a formation below the packer assembly 12, orthe tubing ,10 can be employed for the passage of treating fluids intothe formation, such as in fracturing or acidizing opera tions.

If it is again desired to. disconnect the tubing 10 from the packerassembly '12, the tension on the tubing 10 is released and the tubing 10is lowered and weight from the surface is applied throughthe shoulder 32to the upper end of the sleeve ring 28, until the sleeve ring 28 isforced into the latch ring 24 in the same position as shown in Figure 1.Then the following procedures as illustrated by Figures 2 and 3 areperformed.

Upward movement of the tubing 10 along with the attached cylindricalbody 14a of the tubing, latch assembly 14 pulls the tubing extensionupwardly until the shoulder thereon contacts the lower end of thefingers 26a. Continued upward movement of the tubing 10 and tubingextension 25 forces the fingers 26a upwardly through the sleeve ring 28.As the fingers 26a pass through the sleeve ring 28, they .are compressedinwardly and the shoulders 2612 will pass through the latch ring 24.When the shoulder 26!; contacts the lower end of the sleeve ring 28,further upward movement forces the sleeve ring 28 out of the latch ring24 and the component parts are in the position shown in Figure 3. It isreadily seen that the tubing 10 with the attached tubing latch assembly14 is now free of the packer assembly 12 and can be removed from thecased well bore.

Thus it can be seen that once the packer assembly 12 is set to engagethe cased well bore 16 and the tension sleeve 15 parted, longitudinalmovement of the tubing will successively latch and unlatch the tubing 10from the packer assembly 12 by means of the unique tubing latch assembly14.

Although the invention has been described in terms of a specificembodiment, it should be understood that this was by way of illustrationonly and that the invention is not limited thereto. Accordingly,modifications of the invention are contemplated without departing fromthe spirit of the described invention or the scope of the appendedclaim.

I claim:

A releasable latching device for connecting a section of well tubingor'the like to a hollow packer assembly having a radially extendinginner projection comprising,

' in combination, a cylindrical body adapted to be connected to andextend downwardly from said tubing, said body having upwardly anddownwardly facing shoulders with a section of reduced diametertherebetween, a ringlike member slidably encircling the section ofreduced diameter and limited in movement by the shoulders on said body,said ring-like member having a pluralityof outwardly biased downwardlyextending fingers adapted to engage said inner projection, said fingersbeing constructed and arranged to move radially inward and pass throughsaid inner projection upon contacting the same when said body is moveddownwardly relative to said packer assembly, said fingers havingupwardly facing shoulders near the lower ends thereof for engaging saidinner projection from below to limit upward movement of said bodyrelative to said packer assembly after said fingers have passed throughsaid inner projection, and a sleeve memberencircling said ring-likemember and slidable between the downwardly facing shoulder on said bodyand the upwardly facing shoulders on said fingers, said sleeve memberbeing adapted to frictionally engage said inner projection when saidbody is moved farther downwardly relative to said packer assembly aftersaid fingers have passed through said inner projection and being adaptedto thereafter engage said. fingers from above to move the shoulders onsaid fingers radially inward out of engageable relation to said innerprojection when said body is thereafter moved upwardly relative to saidpacker assembly, whereby said body may be removed from said packerassembly.

References Cited in the file of this patent UNITED STATES PATENTS

